Fastener



FIG. 1 is a front view of a fastener showing our new design in accordance with the present invention;

FIG. 2 is a rear view thereof;

FIG. 3 is a right side view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a bottom view thereof; and,

FIG. 6 is an upper right top perspective view thereof.

The portions of the fastener shown in broken lines form no part of the claimed design. 

CLAIM The ornamental design for a fastener, as shown and described. 